A chip type coil-based fluxgate current sensor, comprising: a magnetism gathering iron core, a chip type coil, an integral filtering module, a signal driving module, a voltage acquisition module, and a signal amplification module which are connected in sequence. The chip type coil comprises a first high-resistance silicon wafer and a second high-resistance silicon wafer which are bonded with each other; a built-in cavity is formed between involution surfaces of first high-resistance silicon wafer and second high-resistance silicon wafer, and multiple solenoid cavities filled with coil materials are provided around the periphery of the cavity; a cavity opening is formed at one end after involution of first high-resistance silicon wafer and second high-resistance silicon wafer. The magnetism gathering iron core is inserted into the cavity of the chip type coil by means of the cavity opening. The present current sensor is small in size and stable in signal.

A current sensor for detecting a magnitude of a current flowing through a measuring object has a magnetic core having a first magnetic core and a second magnetic core that is arranged magnetically in parallel to the first magnetic core, wherein the first magnetic core has a magnetic permeability that is higher than that of the second magnetic core in a first frequency band, and the first magnetic core has a magnetic permeability that is lower than that of the second magnetic core in a second frequency band, the second frequency band being higher than the first frequency band, and the current sensor detects the magnitude of the current in a frequency band that is constituted by combining the first frequency band and the second frequency band.

An integrated magnetic current sensor is provided. Aspects include a first transformer comprising a magnetic core, a first primary winding and a first secondary winding, a voltage source configured to supply a first alternating current (AC) voltage to the first secondary winding, a second transformer comprising, the magnetic core, a second primary winding, a second secondary winding, and a third secondary winding, wherein the first primary winding and the second primary winding are connected in series, and a bi-directional current source configured to bias a magnetic field in the magnetic core by supplying a current to the second secondary winding responsive to a sense current flowing through the first primary winding and the second primary winding.

A current transformer according to the present invention may comprise a magnetic core, a secondary coil, and a magnetic flux compensation member. A main circuit of an air circuit breaker penetrates the magnetic core. In addition, the secondary coil is arranged to be adjacent to the magnetic core, and a secondary current is induced through a current flowing in the main circuit. In addition, the secondary coil supplies the induced secondary current to a relay. The magnetic flux compensation member may be coupled to the magnetic core so as to correct magnetic flux of the secondary coil.

In described examples, a magnetic sensor includes a waveguide that encapsulates dipolar molecules. A mm-wave electromagnetic field is launched into the waveguide, travels through the dipolar molecules, and is then received after passing through the dipolar molecules. The frequency of the mm-wave electromagnetic signal is swept across a range that includes an intrinsic quantum rotational state transition frequency (Fr) for the dipolar molecules. Absorption peaks in accordance with the Zeeman effect are determined. A strength of a magnetic field affecting the magnetic sensor is proportional to a difference in the frequencies of the absorption peaks.

Fluxgate current transducer including a fluxgate device comprising a saturable soft magnetic core and an excitation coil, and a processing circuit comprising a control circuit and a voltage generator connected to the control circuit for generating an alternating current in the excitation coil, the voltage generator generating a voltage oscillating between a maximum positive voltage (+Umax) and a maximum negative voltage (−Umax) configured to alternatingly saturate the soft magnetic core. The control circuit is configured to generate a voltage having an absolute value of amplitude less than an absolute value of said maximum positive voltage (+Umax) and said maximum negative voltage (−Umax) voltage during a variable time window (Tn, Tn+1, Tn+2, Tn+3) after detection of the excitation coil current reaching a threshold current (S3) representative of saturation of the magnetic core during at least a subset of a plurality of alternating voltage periods (P).

An object of the present invention is to provide a magnetic sensor capable of detecting a magnetic field to be measured through closed loop control even when the magnetic field is weak. A magnetic sensor includes magnetic layers 41 and 42 opposed to each other through a magnetic gap G1, a magneto-sensitive element R1 disposed on a magnetic path formed by the magnetic gap G1, and a compensation coil 60 generating canceling magnetic flux ϕ4 to cancel magnetic flux ϕ2 applied to the magneto-sensitive element R1. According to the present invention, magnetic flux ϕ2 flowing in the magnetic layers 41 and 42 each functioning as a yoke is applied to the magneto-sensitive element R1, so that even when a magnetic field to be measured is weak, it can be detected. In addition, closed loop control can be performed due to the presence of the compensation coil 60 that cancels magnetic flux ϕ2.

A flux gate current sensor includes a magnetic core, a measurement winding, an excitation circuit arranged to generate a digital excitation signal, an acquisition circuit arranged to acquire an analog measurement voltage from the terminals of the measurement winding and to produce a digital measurement signal, a demagnetization servocontrol circuit arranged to use the digital measurement signal to produce a digital demagnetization signal for compensating magnetic flux produced by the current that is to be measured, a summing circuit arranged to sum the digital excitation signal and the digital demagnetization signal so as to obtain a digital injection signal, and an injection circuit arranged to produce an analog excitation current from the digital injection signal and to inject the analog excitation current into the measurement winding.

A current sensing device according to the present invention may comprise: a substrate part which includes at least two base substrates stacked in one direction and through which a circuit passes in the one direction; a coil part which is formed on at least one of the base substrates and surrounds the circuit; and a core part which is disposed between the base substrates while being spaced apart from the coil part, and surrounds the circuit.

A current converter contains a primary conductor, a housing through which the primary conductor is led, an inductive alternating-current sensor which has at least one secondary coil arranged in the housing, and a compensation current sensor having a compensation coil arranged in the housing for producing a compensation magnetic field, which compensates a primary magnetic field produced by the primary conductor. A magnetometer is further provided for detecting a sum of the primary magnetic field and the compensation magnetic field.